Method and apparatus for treating filaments



Jan. 10, 1928.

G. E. INMAN `METHOD AND APPARATUS FOR TREATING FILAMENTS ZSZYENTDH .5L-'DEEE Zi INA/IAM :Ey s E Q f M,

A ill l 1%@ A ,A ,M 2 M g Patented Jan. 10, 1928.

UNITED STATES 4PATENT OFFICE.lv

GEORGE E. INMAN, F EAST CLEVELAND, OHIO, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METHOD AND APPARATUS FOR TREATING FILMENTS.

Application filed J'une 9, 1926. Serial No. 114,808.

My invention relates to -methods and apparatus for coating incandescent lamp filaments and other articles of like proportions. More particularly, my invention relates to methods and apparatus for applying the socalled getter to coiled metal filaments. Getters are materials, usually non-metallic. which are used inincandescent lamps and similar devices in some cases for improving the, vacuum and for preventing discoloration of the bulb. It is desirable that this material be applied uniformly, and this is a more difiicult operation in the 4case of coiled filaments than in that of straight filaments. The present invention is an im? provement on that disclosed in my co-pending application, Serial No. 107,883, filed May 10, 1926. The specific method disclosed in that application consists in spraying getter material upon the filaments which are held in a recepta le and simultaneously causing a whirling movement of the filaments in the receptacle. According to the present invention, the filaments are supported in a receptacle connected to the bottom of which is a pipe through which air pressure is directed and means are provided whereby the getter is incorporated with the blast so that the blast accomplishes a double purpose of gettering and stirring up the filaments. One advantage which this has over the specific method disclosed in my application above referred to is that there is less tend ency of the tanglin'g of the coils, and this is of particular importance in the lgettering ofthe smaller diameter filaments which are more easily tangled. Further features and advantages of my invention will 4appear from a description which follows of a species thereof.

In the drawing, Fig. 1 is an elevation partially in section of an apparatus embod ing my invention; Fig. 2 is an enlarged ragmentary vertical section through the spray nozzle; Fig. 3 is a top plan view of the spray nozzle; andv Fig. 4 shows a portion of a filament coil on an enlarged scale.

The inverted cone or funnel is of brass or other metal which will not be affected by the getter material and contains a number of the filament coils 11. The said funnel is removably supported by an arm 12 which has projecting therefroma stop pin 13 and is held by the socket bracket 14. A spring 15 surrounds the end of the arm 12 within the socket, said arm being provided with a pin 16 engaging the end of the spring. The arrangement lis such that the arm 12 may be pulled out from the, socket but is 'normally retracted by the spring 15 with the pin 13 resting in the notch in the socket end. The bracket 14 is supported on a stand ard 17 carried by the base 18. The getter container or graduatev 19 is supported on an adjustable bracket 20 carried by the standard 17. This container is adapted to receive a quantity of the getter material comprising finely divided chemicals such as cryolite in suspension in a volatile liquid carrier. One mixture which has been'found to be suitable was made by adding two hundred ams of cryolite linely divided to one hun red and fifty grams of lacquer containing amyl acetate and then diluting by adding to one part of the cryolite lacquer mixture four parts by volume of a mixture of 80% methyl alcohol and 20% ether. A nozzle tube 21 extends vertically upward from a point near the battom of the graduate 19 and the upper end thereof is screwed into a nozzle 22, the latter having a 'flange 23 which is held in aseat inthe bottom of the nozzle adjusting.

member 24 by a lock nut 25. The internal thread on member 24 engages the external thread on the spray nozzle 26 through the center of which'extends the getter material nozzle 22, all of said parts being supported at the bottom of the tubular portion of the funnel 10. An air blast conduit 27 controlled by valve 28 communicates through the wall of the funnel extension 10 with an nular chamber 29 formed'between nozzle 26 and said funnel extension 10 which chamber communicates by means of ports 30 with an annularpassage 31 formed between the nozzle members 22 and 26. A needle 32 extends up through the center of the nozzle members 21 and 22, and its point is disposed in the -constricted ,end of the member 22. The said needle is bent so that its opposite end is held by one jaw of a control member 33 (Fig. 1) by means of which the operator can move the needle point up and .down to control the opening at the end of the getter nozzle, or, if need be, to interrupt the flow of the getter material. An injector tube 34 is provided extending to the bottom of the graduate 19 and with its other end in a suitable position so that air may be injected to stir up the getter mixture. Over the top of blown and simultaneously coated.

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the tunnel l is disposed the i'ilament coating; chamber up into which the filaments are fis specifically shown in the drawing, this chamber is walled by a cylinder 35, preferably ot glass, which is supported by the standard 17 a strap 36 surrounding the same being removably and adjustably supported on a bracket 3? which is pivoted on the standard l?. The arrangement is such that the cylinder can be raised trom the tunnel l0 and swung out of line therewith until a pin 38 carried by the bracket 3'? engages a stationary rest supported trom the aforesaid standard. y

The cylinder 35 is provided at its upper with ventilated cover nich may be the tunnel an annular rThe said cover corni member l0 and. top mei el. The annular member is construe'.eu so that it-rests upon the top rim of the cylinder and is held in position by means ot a plurality of set screws e2. A. secondary support is also provided for the said annular member Lt() which consists of, a. ystrap i3 having extending therefrom the vertical braces all which are attached to the annular member t() by means ot the screws iin the upper portion oif the annular member 40 is supported the top member 4l by the set screws 46. rllhe top member is adjustably spaced from the annular member t() so as to allow the escape ot gases while at the same time retaining the filaments in the cylinder 35.

ln operation, with the cylinder 35 swung over so that the bracket pin 38 rests on the I stop 39, a quantity ot filament coils are placed in the funnel 10. The cylinder is then swung back to the position shown in the drawing and the air pressure is turned inatteso on causing the getter solution to be aspirated up into the blast. rlhis causes the filament coils to be tossed upwardly into the gettering chamber giving' the appearance ot a fountain. rlhe gettering mixture is so constituted that it dries very quickly upon striking the coils and the result is that they are rapidly and evenly coated with the getter material. This usually takes a few minutesI but, obviously, the time is determinable by trial. i quick stoppage ot the lettering action can be made by the operator by means ot the control 33 after which the blast may be turned oft. fhetop is then swung oil ol: the tunnel and the bracket 2O swungr trout under the graduate i9 by the opera-tor who then removes the graduate. rl`he filaments may then he dumped from the tunnel i0 by pulling out the arm l2 against the action ot tne spring 15 so that the pin 13 clears the notch and then inverting' the tunnel.

lhat l claim as new and to secure by Letters latent ot the United States, is z# l. The method oi' coating filaments which consists in projecting a number thereot into a confined space by a blast containing the coating material.

2. The method ot coating filaments which consists in projecting a number thereof in an upward direction into a confined space, by a blast containing the coating material.

3. An ,apparatus comprising a substantially vertically disposed chamber having communicating with the bottom thereof means tor supporting a number of filament-s, means Jfor causinga blast to be directed iiito the bottom of said chamber, and means for incorporating coating material in said blast.

ln witness whereof, l have hereunto set my hand this Lith day ot June, 1926.

1 GEORGE E. INMAN. 

